1. Field of the Invention
The present invention relates, generally, to packaging machinery. More particularly, the invention relates to devices for applying glue to cartons on a packaging machine.
2. Background Information
A common type of packaging machine processes a large volume of individual articles by arranging and grouping the articles, loading a group of articles into a carton, closing and sealing the cartons, and dispensing the loaded cartons to an area where they are consolidated for shipping. A typical carton is constructed of paperboard or corrugated paper and has flaps which are folded closed and sealed with glue.
The state of the art includes various devices for applying glue to cartons on a packaging machine. A common type of glue used to seal paperboard cartons is a hot-melt material. The glue is heated in a central container and pumped to individual dispensing stations. The dispensing stations and hoses between the dispensing stations and the central container often are also heated to keep the glue at the proper viscosity for dispensing. Devices on the dispensing stations have at least one nozzle, and often have a plurality of nozzles through which the glue is applied to flaps of cartons as cartons pass by the dispensing station.
Prior art devices for applying glue to cartons are believed to have significant limitations and shortcomings. The devices are often custom-made wherein the nozzles are in a fixed predetermined location. A custom-made device may be relatively expensive. As carton size changes for different size articles or different group configurations, the position of the flaps typically changes, thereby requiring a change in the position of the nozzles on the dispensing station. A glue dispensing station on a packaging machine typically has a number of custom-made devices, each with a different nozzle configuration for a specific carton configuration run on the machine. An inventory of several custom-made devices for a dispensing station is relatively expensive.
When a changeover is made on the packing machine to run a different carton, one glue dispensing device is removed and another device is installed. Such an operation can be time consuming and risk damage to the devices. The devices are hot from the glue, and care must be taken that personnel are not burned when removing a device. The devices may be allowed to cool before being removed, which takes time. Hoses attached to a device must be disconnected and reattached either to the devices or to the glue supply. This risks damage to the hoses each time a connection is changed. Air may also be undesirably introduced into the system by the new hose connection. The new device and hoses must be heated to the working temperature before the operation of the machine can be resumed. This also takes time.
Such devices may be rather bulky requiring a space of one to two linear feet of the packaging machine. On a packaging machine where space is limited, this may be too much.
Applicant's invention overcomes the limitations and shortcomings of the prior art by providing an apparatus which uses a plurality of small, standard glue dispensing devices and provides for positional adjustment of them so the same devices can be used for all carton configurations run on a packaging machine. The apparatus and dispensing devices are cost-effective and require less than one linear foot of space on the packaging machine.